AWS_IO_TLS_ERROR_WRITE_FAILURE when connecting to IoT Core with Cognito Authenticated User

Hi. The same endpoints work fine if I use certs, but when I switch the auth to Cognito Authenticated users, it can't connect. The user authenticates and gets back credentials (secret key, etc.). Any help would be appreciated. I have a feeling it is a permissions issue, but I have no idea.

Here's the snippet (logs below):

cognito_id_pool_endpoint = f"cognito-identity.{os.getenv('COGNITO_REGION')}.amazonaws.com"
l = [(os.getenv('COGNITO_USER_POOL_URL'), idtoken)] # USER POOL

provider = auth.AwsCredentialsProvider.new_cognito(
    endpoint=cognito_id_pool_endpoint,
    identity=identityId,
    logins=l,
    tls_ctx=io.ClientTlsContext(io.TlsContextOptions()))

mqtt_connection = mqtt_connection_builder.websockets_with_default_aws_signing(
    endpoint=os.getenv('IOT_ENDPOINT'),
    region=os.getenv('IOT_REGION'),
    client_id=f'my-device:{uuid.uuid4()}',
    on_connection_failure=on_connection_failure,
    on_connection_interrupted=on_connection_interrupted,
    on_connection_resumed=on_connection_resumed,
    credentials_provider=provider)

connect_future = mqtt_connection.connect()

connect_future.result()
logging.info('Connected!')

Here are the relevant logs:

[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [event-loop] - id=0x14e965150: scheduling 
task 0x14e9986e0 in-thread for timestamp 0
[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [task-scheduler] - id=0x14e9986e0: 
Scheduling socket_written_task task for immediate execution
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [tls-handler] - id=0x14e99b9b0: bytes read 0
[ERROR] [2024-01-12T00:59:46Z] [000000016b9ff000] [tls-handler] - id=0x14e99b9b0: error 
reported during SSLRead. OSStatus code -9805
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [tls-handler] - id=0x14e99b9b0: connection 
shutting down gracefully.
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [socket-handler] - id=0x14e99b560: out of 
 data to read on socket. Waiting on event-loop notification.
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [socket] - id=0x14e998f00 fd=23: is writable
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [socket] - id=0x14e998f00 fd=23: processing 
write requests, invoked by the event-loop
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [event-loop] - id=0x14e965150: running 
scheduled tasks.
[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [task-scheduler] - id=0x14e9986e0: Running 
socket_written_task task with <Running> status
[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: beginning 
shutdown process
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: shutting down 
slot 0x14e99a7c0 (the first one) in the read direction
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: shutting down 
slot 0x14e99a7c0, with handler 0x14e99b560 in read direction with error code 0
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [socket-handler] - id=0x14e99b560: shutting 
down read direction with error_code 0
[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: handler 
0x14e99b560 shutdown in read dir completed.

[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: Websocket 
handler shutting down dir=READ error_code=0 immediate=0.

[INFO] [2024-01-12T00:59:46Z] [000000016b9ff000] [mqtt-client] - id=0x14e161c00: sending 
disconnect message as part of graceful shutdown.
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: acquired 
message 0x14e98ce70 of capacity 3 from pool 0x14e987c30. Requested size was 3
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [mqtt-client] - id=0x14e161c00: Acquiring 
memory from pool of required_length 3
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: sending write 
message of size 2, from slot 0x12f0bf120 to slot 0x12dedc3c0 with handler 0x14e1a8a20.

[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: Enqueuing outgoing frame with opcode=2(binary) length=2 fin=T [TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: Scheduling synced data task.

[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: Outgoing CLOSE frame queued, handler will finish shutdown once it's sent. [TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: websocket_close_timeout task will be run at timestamp 5628888184394625 [TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: scheduling task with wrapper task id 0x14e1a8c18.

[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [task-scheduler] - id=0x14e1a8c18: Scheduling websocket_close_timeout task for future execution at time 5628888184394625

[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [task-scheduler] - id=0x14e1a8a78: Running websocket_move_synced_data_to_thread task with <Running> status

[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: Websocket 
will send no more data, future attempts to send will get error 2066 
(AWS_ERROR_HTTP_WEBSOCKET_CLOSE_FRAME_SENT).
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: Sending 
aws_io_message of size 14 in write direction.
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: sending write 
message of size 14, from slot 0x12dedc3c0 to slot 0x14e99d4e0 with handler 0x14e99d8a8.
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: sending write 
message of size 14, from slot 0x14e99d4e0 to slot 0x14e998b00 with handler 0x14e99b9b0.
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [tls-handler] - id=0x14e99b9b0: bytes 
written: 
0
[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [tls-handler] - id=0x14e99b9b0: SSLWrite 
failed with OSStatus error code -9805.
[ERROR] [2024-01-12T00:59:46Z] [000000016b9ff000] [http-connection] - id=0x14e99d8a0: 
Destroying write message without passing it along, error 1031     (AWS_IO_TLS_ERROR_WRITE_FAILURE)
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: Completed 
outgoing frame=0x12f0b3750 opcode=2(binary) payload-length=2 with error_code 1031 
(AWS_IO_TLS_ERROR_WRITE_FAILURE).
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: Completed 
outgoing frame=0x12f0b45f0 opcode=8(close) payload-length=0 with error_code 1031 
(AWS_IO_TLS_ERROR_WRITE_FAILURE).
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: 
aws_io_message did not finish writing to socket, error 1031 (AWS_IO_TLS_ERROR_WRITE_FAILURE).
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [websocket] - id=0x14e1a8a00: Finishing 
websocket handler shutdown.
[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [channel] - id=0x14e999540: handler 
0x14e1a8a20 shutdown in write dir completed.
[TRACE] [2024-01-12T00:59:46Z] [000000016b9ff000] [http-connection] - id=0x14e99d8a0: Channel 
shutting down in write direction with error code 0 (AWS_ERROR_SUCCESS).
[DEBUG] [2024-01-12T00:59:46Z] [000000016b9ff000] [http-stream] - id=0x14e99ecb0: Stream 
completed with error code 2058 (AWS_ERROR_HTTP_CONNECTION_CLOSED).